The overall objectives of this Clinical Radiation Oncology Research Center will continue to be: 1. At the clinical level, the development, operation and coordination of local and national cooperative clinical therapeutic trials, together with clinical, pathologic and physical dosimetric investigations as related to cancer radiation therapy; 2. At the basic experimental research level, the systematic, multidisciplinary delineation of the fundamental cellular, tissue, vascular, circulatory, and connective tissue properties (ultrastructural, cytokinetic, histopathologic, histochemical, physiologic, immunologic) of transplanted, induced, or spontaneous malignant neoplasms of various kinds (comparative oncology) and the in vivo and in vitro responses of these neoplasms and their components, as well as those of normal organs, during and after radiation exposure in various temporal modes, with and without adjunctive chemical, physical or physiologic modifying agents; and 3. The translation of clinical and experimental radiobiologic, radiopathologic, and oncologic research data into experimental animal models of clinical radiotherapeutic problems for investigation of their solution.